Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
quoc ban » quoc bao, quoc lan, quoc quan
xuc ban » duc ban, cuc ban, xuat ban
va cham » va chat, va tham
hieu va » lieu va, hieu qua
tang xa » trang xa, lang xa, tang ha
tang ma » mang may, tang van
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y ((tang xa) or (tang ma)) hoi. hieu va cham ((xuc ban) OR (quoc ban)) hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y ((tang xa) OR (tang ma)) hoi. hieu va cham ((xuc ban) OR (quoc ban)) hanh vi cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach y ((tang xa) or (tang ma)) hoi. hieu va cham ((xuc ban) OR (quoc ban)) hanh vi cua tu".
• Adding a wildcard symbol may retrieve word variants: hoc sach y ((tang xa) or (tang ma)) hoi. hieu va cham ((xuc ban) OR (quoc ban)) hanh vi cua tu*.